A prism motor, a method for detecting the rotation angle of a prism motor, and an imaging module

Abstract

An embodiment of the present invention relates to the field of imaging technology, and discloses a prism motor, a method for detecting the rotation angle of the prism motor, and an imaging module. The prism motor in the present invention includes: a first electrode plate located on the surface of the prism base; a second electrode plate located on the surface of the prism carrier, and the second electrode plate is disposed opposite to the first electrode plate; the first electrode plate and the second electrode plate form a capacitor. When the prism carrier rotates unidirectionally around the first rotation axis, the facing area between the first electrode plate and the second electrode plate increases and the distance between the first electrode plate and the second electrode plate decreases, or the facing area between the first electrode plate and the second electrode plate decreases and the distance between the first electrode plate and the second electrode plate increases; a processing unit is configured to determine the rotation angle of the prism carrier according to the capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate. It is beneficial to the miniaturization of the motor and improves the detection effect of the offset angle of the prism carrier.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of imaging technology, and in particular, to a prism motor, a method for detecting the rotation angle of the prism motor, and an imaging module. Background Art

[0002] Currently, in a periscope imaging module, a prism motor is usually used to refract incident light. By folding the incident light, the focal length of the imaging module is extended, thereby enhancing the zoom ability of the imaging module. When using the imaging module to collect images, the propagation angle of the incident light can be changed by rotating the prism carrier in the prism motor, and thus the imaging effect of the imaging module can be changed. Usually, the rotation angle of the prism carrier is detected by an internal Hall sensor or a driving chip with Hall detection function.

[0003] The inventors have found that the rotation angle detection function of the current periscope imaging module has at least the following disadvantages: The Hall sensor or the driving chip with Hall detection function needs to cooperate with the corresponding sensing magnet to measure the angle. Setting the Hall sensor and the corresponding magnet inside the prism motor will occupy a large internal space of the motor, which is not conducive to the miniaturization of the motor. On the other hand, when the internal space of the motor is fixed, the Hall sensor and the magnet occupy a large space, which will also limit the volume of the driving module for driving the prism motor, and is not conducive to improving the driving ability of the prism motor. Summary of the Invention

[0004] Embodiments of the present invention aim to provide a prism motor, a method for detecting the rotation angle of the prism motor, and an imaging module, which save the internal volume of the prism motor occupied by the implementation of detecting the rotation angle of the prism motor, are conducive to the miniaturization of the motor, and improve the detection effect of the offset angle of the prism carrier.

[0005] To solve the above technical problems, an embodiment of the present invention provides a prism motor, including: a prism base; a prism carrier, the prism carrier is spaced apart from the prism base, and the prism carrier is rotatable relative to the prism base; a first electrode plate, the first electrode plate is located on the surface of the prism base; a second electrode plate, the second electrode plate is located on the surface of the prism carrier, and the second electrode plate is disposed opposite to the first electrode plate; the first electrode plate and the second electrode plate form a capacitor. When the prism carrier rotates unidirectionally around a first rotation axis, the facing area between the first electrode plate and the second electrode plate increases and the distance between the first electrode plate and the second electrode plate decreases, or the facing area between the first electrode plate and the second electrode plate decreases and the distance between the first electrode plate and the second electrode plate increases; a processing unit, the processing unit is configured to determine the rotation angle of the prism carrier according to the capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate.

[0006] An embodiment of the present invention further provides a method for detecting the rotation angle of a prism motor, which is applied to the above-mentioned prism motor. The method includes: determining an initial capacitance signal generated by a capacitance formed by a first electrode plate and a second electrode plate at an initial position of a prism carrier; determining a current capacitance signal when the capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate changes; and determining the rotation angle of the prism carrier according to the difference between the current capacitance signal and the initial capacitance signal.

[0007] An embodiment of the present invention further provides a photographing module, which includes the above-mentioned prism motor, a lens, and a photosensitive chip; incident light entering the photographing module is reflected by the prism motor and then passes through the lens to reach the photosensitive chip.

[0008] Compared with the prior art, in the embodiment of the present invention, a first electrode plate is arranged on a prism base and a second electrode plate is arranged on a prism carrier, and a capacitance is formed by the first electrode plate and the second electrode plate. The rotation angle of the prism carrier is determined by the change of the capacitance signal. In the motor, a smaller-volume electrode plate is used instead of a Hall sensor, saving the internal volume of the prism motor occupied by the implementation of detecting the rotation angle of the prism motor, which is beneficial to the miniaturization of the motor. In addition, when the prism carrier rotates unidirectionally, the facing area and the spacing between the first electrode plate and the second electrode plate will be changed simultaneously, and the change of the facing area and the change of the spacing have the same influence on the capacitance signal, that is, both the change of the facing area and the change of the spacing will cause an increase in the capacitance signal, or both changes will cause a decrease in the capacitance signal. Therefore, the simultaneous change of the facing area and the spacing will make the amplitude of the change of the capacitance signal larger under the condition of the same-angle rotation, resulting in more sensitive detection of the rotation angle of the prism carrier and improving the detection effect of the offset angle of the prism carrier.

[0009] In addition, the number of the first electrode plates is an even number, and a plurality of the first electrode plates are symmetrically arranged based on the first rotation axis of the prism carrier; the number of the second electrode plates is an even number, and a plurality of the second electrode plates are symmetrically arranged based on the first rotation axis of the prism carrier; the first electrode plates and the second electrode plates are in one-to-one correspondence, and a capacitance is formed by each pair of the first electrode plate and the second electrode plate; the processing unit is configured to determine the rotation angle of the prism carrier according to the capacitance signals generated by a plurality of capacitances formed by the first electrode plates and the second electrode plates. By increasing the number of electrode plates to increase the number of capacitances for detecting the rotation angle, and through comprehensive analysis of the capacitance signals of multiple groups of capacitances, the accuracy of detecting the rotation angle can be further improved.

[0010] In addition, the first electrode plate is symmetrically arranged based on the second rotation axis of the prism carrier, and the second electrode plate is symmetrically arranged based on the second rotation axis of the prism carrier; wherein, the first rotation axis and the second rotation axis are perpendicular to each other. When the prism motor can rotate in multiple directions, by setting the electrode plates as a symmetric structure, it can ensure that the change degrees of the capacitance signals of multiple groups of capacitors respectively formed by the multiple electrode plates are approximately the same during rotation, thereby facilitating the elimination of the influence of the rotation angles in other directions on the detection result as much as possible through subsequent calculation methods and improving the accuracy of calculating the rotation angle in a single direction.

[0011] In addition, the length of the first electrode plate is greater than the length of the second electrode plate; wherein, the defined length direction is consistent with the direction of the first rotation axis. This can reduce the influence of the rotation angle in other directions (such as the second rotation axis) on the change in the magnitude of the capacitance signals generated by the first and second electrode plates of the first rotation axis.

[0012] In addition, the prism motor further includes: a third electrode plate located on the surface of the prism base; a fourth electrode plate located on the surface of the prism carrier, and the fourth electrode plate is arranged opposite to the third electrode plate; the third electrode plate and the fourth electrode plate form a capacitor. When the prism carrier rotates in a single direction around the second rotation axis, the facing area between the third electrode plate and the fourth electrode plate increases and the distance between the third electrode plate and the fourth electrode plate decreases, or the facing area between the third electrode plate and the fourth electrode plate decreases and the distance between the third electrode plate and the fourth electrode plate increases; wherein, the first rotation axis and the second rotation axis are perpendicular to each other; a processing unit for jointly determining the rotation angle of the prism carrier in space according to the capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate, and the signal generated by the capacitor formed by the third electrode plate and the fourth electrode plate. This can design different electrode plate structures for corresponding detection when the prism carrier can rotate in multiple directions.

[0013] In addition, the number of the third electrode plates is an even number, and the third electrode plates are symmetrically arranged based on the second rotation axis of the prism carrier; the number of the fourth electrode plates is an even number, and the fourth electrode plates are symmetrically arranged based on the second rotation axis of the prism carrier; the third electrode plates and the fourth electrode plates correspond one by one, and each pair of the third electrode plate and the fourth electrode plate forms a capacitor.

[0014] In addition, the planes where the first electrode plate and the second electrode plate are located are both parallel to the first rotation axis, and the planes where the third electrode plate and the fourth electrode plate are located are both parallel to the second rotation axis.

[0015] In addition, a part of the positive projection of the first electrode plate in the direction of the second electrode plate falls outside the second electrode plate, and a part of the positive projection of the second electrode plate in the direction of the first electrode plate falls outside the first electrode plate. Description of the Drawings

[0016] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements. Unless otherwise stated, the drawings in the figures do not constitute a scale limitation.

[0017] Figure 1 is a schematic three-dimensional structure diagram of a prism motor according to an embodiment of the present solution;

[0018] Figure 2 is a schematic cross-sectional structure diagram of a prism motor according to an embodiment of the present solution;

[0019] Figure 3 is a schematic structure diagram of a prism motor when the second electrode plate rotates around the first rotation axis according to an embodiment of the present solution;

[0020] Figure 4 is a schematic structure diagram of a setting manner of a first electrode plate and a second electrode plate of a prism motor according to an embodiment of the present solution;

[0021] Figure 5 is a schematic structure diagram of another setting manner of a first electrode plate and a second electrode plate of a prism motor according to an embodiment of the present solution;

[0022] Figure 6 is a schematic diagram of the change in the spatial position of a prism motor when the second electrode plate rotates around the first rotation axis according to an embodiment of the present solution;

[0023] Figure 7 is a schematic diagram of the simulation result of a prism motor according to an embodiment of the present solution;

[0024] Figure 8 is a schematic diagram of the comparison of the sizes of the first electrode plate and the second electrode plate of a prism motor according to an embodiment of the present solution;

[0025] Figure 9 is a schematic structure diagram of a prism motor when the second electrode plate rotates around the second rotation axis according to an embodiment of the present solution;

[0026] Figure 10 is a schematic overhead view of a setting manner of a third electrode plate and a fourth electrode plate of a prism motor according to an embodiment of the present solution;

[0027] Figure 11 is a schematic overhead view of another setting manner of a third electrode plate and a fourth electrode plate of a prism motor according to an embodiment of the present solution;

[0028] Figure 12 It is a structural overhead view of another setting method of the third electrode plate and the fourth electrode plate in the prism motor according to an embodiment of the present solution;

[0029] Figure 13 It is a schematic diagram of the positional relationship between the first electrode plate and the second electrode plate pair in the prism motor according to an embodiment of the present solution;

[0030] Figure 14 It is a schematic diagram of a shape of the first electrode plate and the second electrode plate pair in the prism motor according to an embodiment of the present solution;

[0031] Figure 15 It is another schematic diagram of a shape of the first electrode plate and the second electrode plate pair in the prism motor according to an embodiment of the present solution;

[0032] Figure 16 It is yet another schematic diagram of a shape of the first electrode plate and the second electrode plate pair in the prism motor according to an embodiment of the present solution;

[0033] Figure 17 It is a flowchart of the rotation angle detection method of the prism motor according to an embodiment of the present solution;

[0034] Figure 18 It is a schematic diagram of the structure of the shooting module according to an embodiment of the present solution. Detailed implementation manners

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present invention, many technical details are provided to help readers better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions required to be protected by the present invention can still be implemented.

[0036] The division of the following embodiments is for convenience of description and should not constitute any limitation to the specific implementation manners of the present invention. The embodiments can be combined and cross-referenced with each other on the premise of no contradiction.

[0037] The embodiments of the present invention relate to a prism motor, as Figures 1 to 2As shown in the figure, the prism motor includes: a prism base 100; a prism carrier 200, which is spaced apart from the prism base 100 and can rotate relative to the prism base 100; a first electrode plate 301 located on the surface of the prism base 100; a second electrode plate 302 located on the surface of the prism carrier 200 and disposed opposite to the first electrode plate 301; the first electrode plate 301 and the second electrode plate 302 form a capacitor. When the prism carrier 200 rotates unidirectionally around the first rotation axis, the facing area between the first electrode plate 301 and the second electrode plate 302 increases and the distance between the first electrode plate 301 and the second electrode plate 302 decreases, or the facing area between the first electrode plate 301 and the second electrode plate 302 decreases and the distance between the first electrode plate 301 and the second electrode plate 302 increases; a processing unit for determining the rotation angle of the prism carrier 200 according to the capacitance signal generated by the capacitor formed by the first electrode plate 301 and the second electrode plate 302.

[0038] In the embodiment of the present invention, compared with the prior art, the first electrode plate 301 is provided on the prism base 100 and the second electrode plate 302 is provided on the prism carrier 200, and the capacitance is formed by the first electrode plate 301 and the second electrode plate 302. The rotation angle of the prism carrier 200 is determined by the change of the capacitance signal, so as to compensate for the angle change caused by jitter. In the motor, a smaller-volume electrode plate is used instead of the Hall sensor, saving the internal volume of the prism motor occupied by the anti-shake technology and facilitating the miniaturization of the motor. In addition, when the prism carrier 200 rotates unidirectionally, the facing area and the distance between the first electrode plate 301 and the second electrode plate 302 will be changed simultaneously, and the change of the facing area and the change of the distance have the same influence on the capacitance signal, that is, both the change of the facing area and the change of the distance will cause an increase in the capacitance signal, or both changes will cause a decrease in the capacitance signal. Therefore, the simultaneous change of the facing area and the distance will make the amplitude of the capacitance signal change larger under the condition of the same-angle rotation, resulting in more sensitive detection of the angle rotation of the prism carrier 200 and improving the detection effect of the offset angle of the prism carrier 200.

[0039] In addition, as Figure 2 shown, the prism base 100 includes: a base bottom 101 and a base side 102. The first electrode plate 301 can be disposed on the base bottom 101 and / or the base side 102 according to the rotation direction of the prism carrier 200.

[0040] As Figure 1 and Figure 3As shown, the X-axis direction is the direction in which the incident light enters the prism motor, the Z-axis direction is the direction in which the incident light perpendicularly enters the lens after reflection, and the Y-axis is perpendicular to the XZ plane. Taking the rotation of the prism carrier 200 around the first rotation axis (Y-axis) as an example, the first electrode plate 301 is fixed on the prism base 100. Before the prism carrier 200 rotates, the position of the second electrode plate 302 is as shown in Figure 3 the solid line position in. When the prism carrier 200 rotates by an angle θ around the first rotation axis (Y-axis), the position of the second electrode plate 302 is as shown in Figure 3 the dashed line position in. The facing area between the rotated first electrode plate 301 and the second electrode plate 302 decreases, and the average distance between the first electrode plate 301 and the second electrode plate 302 increases, resulting in a change in the capacitance signal corresponding to the capacitance formed by the first electrode plate 301 and the second electrode plate 302. The rotation angle θ of the second electrode plate 302 can be determined through the change of the capacitance signal. Since the second electrode plate 302 is fixed on the prism carrier 200, that is, the rotation angle of the second electrode plate 302 has a corresponding relationship with the rotation angle of the prism carrier 200. Therefore, the rotation angle of the prism carrier 200 can be obtained according to the rotation angle of the second electrode plate 302, and further the compensation for the angle change of the prism carrier 200 caused by jitter can be completed.

[0041] In addition, the number of the first electrode plates 301 is an even number, and multiple first electrode plates 301 are symmetrically arranged based on the first rotation axis of the prism carrier 200; the number of the second electrode plates 302 is an even number, and multiple second electrode plates 302 are symmetrically arranged based on the first rotation axis of the prism carrier 200; the first electrode plates 301 and the second electrode plates 302 correspond one by one, and each pair of the first electrode plates 301 and the second electrode plates 302 forms a capacitance; the processing unit is used to determine the rotation angle of the prism carrier 200 according to the capacitance signals generated by the multiple capacitances formed by the first electrode plates 301 and the second electrode plates 302.

[0042] Taking the number of both the first electrode plates 301 and the second electrode plates 302 being 2 as an example, as shown in Figures 4 to 5 , the planes where the two first electrode plates 301 and the two second electrode plates 302 are located are both parallel to the first rotation axis (Y-axis), and the two first electrode plates 301 are respectively on both sides of the first rotation axis, and are symmetrically arranged with respect to the first rotation axis. The two second electrode plates 302 are respectively on both sides of the first rotation axis, and are symmetrically arranged with respect to the first rotation axis.

[0043] When the first electrode plate 301 is arranged at the bottom 101 of the base, the second electrode plate 302 is correspondingly arranged at the bottom of the prism carrier 200. In addition, the prism base 100 is a semi-enclosed structure with three sides and one bottom surface. When the first electrode plate 301 is arranged at the rear side of the base in the side part of the base, the second electrode plate 302 is arranged on the prism side surface opposite to the rear side of the base.

[0044] Next, takingFigure 6 Taking the first and second electrode plates of the first rotation axis as an example, the capacitance calculation method caused by the rotation of the second electrode plate will be specifically described. Taking the capacitance calculation of the left electrode plate as an example:

[0045] When the second electrode plate 302 rotates clockwise along the Y-axis, the average distance gap between the first electrode plate 301 and the second electrode plate 302 on the left side in the figure increases. At the same time, the facing area S between the two decreases. The increase in the average distance gap and the decrease in the facing area S will jointly exacerbate the decrease in the capacitance value. Therefore, using this method can accelerate the change of the capacitance, thereby improving the sensitivity of the capacitance.

[0046] The initial plane equation of the second electrode plate 302 on the left side in the figure is:

[0047] = -Rcosα, , ;

[0048] Among them, represents the X-axis coordinate value of the initial plane of the second electrode plate 302, represents the minimum Z-axis coordinate value of the initial plane of the second electrode plate 302 on the left side, represents the maximum Z-axis coordinate value of the initial plane of the second electrode plate 302 on the left side; R represents the distance between the center of the initial plane of the second electrode plate and the origin O, α represents the angle between the line connecting the center of the initial plane of the second electrode plate and the origin O and the X-axis, and m represents the width of the second electrode plate.

[0049] The initial plane equation of the second electrode plate 302 on the left side is:

[0050] = -Rcosα - gap, , ;

[0051] Among them, represents the X-axis coordinate value of the initial plane of the first electrode plate 301, represents the minimum Z-axis coordinate value of the initial plane of the first electrode plate 301 on the left side, represents the maximum Z-axis coordinate value of the initial plane of the first electrode plate 301 on the left side; m represents the width of the first electrode plate (here, it is assumed that the widths of the first and second electrode plates are the same. In actual applications, the first and second electrode plates can be set to different widths); shift represents the offset between the first and second electrode plates in the width direction at the initial position.

[0052] When the prism carrier 200 rotates clockwise by β degrees around the Y-axis, the plane equation of the rotated second electrode plate 302 on the left side is:

[0053] ;

[0054] ;

[0055] Wherein, represents the Z-axis coordinate value of the second plate 302 after rotation, represents the X-axis coordinate value of the second plate 302 after rotation, z represents the Z-axis coordinate value of the second plate 302 before rotation, x represents the X-axis coordinate value of the second plate 302 before rotation, α represents the angle between the line connecting the center of the initial plane of the second plate and the origin O and the X-axis, and β represents the rotation angle of the prism carrier 200.

[0056] From the above equations, the average distance between the first plate 301 and the second plate 302 on the left side of the figure after rotation can be calculated as: is:

[0057] = - ;

[0058] After rotation, the overlapping coordinate range of the first plate 301 and the second plate 302 on the left side of the figure in the Z-axis direction is:

[0059] ;

[0060] ;

[0061] Wherein, represents the maximum Z-axis coordinate value of the initial plane of the second plate 302 on the left side after rotating by an angle β, represents the maximum Z-axis coordinate value of the initial plane of the first plate 301 on the left side, represents the minimum Z-axis coordinate value of the initial plane of the second plate 302 on the left side after rotating by an angle β, represents the minimum Z-axis coordinate value of the initial plane of the first plate 301 on the left side.

[0062] Assuming the length of the plate is L, the capacitance expression of the two plates after rotating by an angle β is:

[0063] ;

[0064] Wherein, is the dielectric constant of the medium between the first plate and the second plate.

[0065] For the calculation method of the above capacitance expression, a simulation calculation is performed to determine the corresponding capacitance signal by rotating by an angle β around the Y-axis. The initial parameters configured are shown in the following table:

[0066]

[0067] According to the initial parameters configured above, the simulation results of the capacitance value changing corresponding to the rotation angle β are as follows Figure 7 As shown, when the prism motor is in normal use, the capacitance has good linearity within the range of the rotation angle β of ±1 degree (60 min), and has good capacitance sensitivity, which is convenient for determining the change in the rotation angle according to the change in the capacitance signal. In addition, if the length of the electrode plate is increased, that is, the initial overlapping area is increased, the change degree of the capacitance signal is more obvious, and the capacitance sensitivity can be further increased.

[0068] In addition, the first electrode plate 301 is symmetrically arranged on the left and right based on the second rotation axis (X axis) of the prism carrier 200, and the second electrode plate 302 is symmetrically arranged on the left and right based on the second rotation axis of the prism carrier 200; wherein, the first rotation axis and the second rotation axis are perpendicular to each other. That is, the first electrode plate and the second electrode plate are symmetrically arranged in pairs with respect to the XY plane. In addition, both the first electrode plate 301 and the second electrode plate 302 are symmetric with respect to the ZX plane. While the prism motor rotates around the first rotation axis, it can also rotate around the second rotation axis. By setting the electrode plates as a centrosymmetric structure, it is ensured that they are symmetric not only with respect to the first rotation axis but also with respect to the second rotation axis. When the prism motor rotates around the axis, the change degrees of the capacitance signals of the multiple capacitors formed by the symmetrically structured electrode plates can be made approximately the same, thereby facilitating the elimination of the influence of the rotation angles in other directions on the detection results as much as possible through subsequent calculation methods and improving the accuracy of the single-direction rotation angle calculation.

[0069] Specifically, the setting method of the first electrode plate and the second electrode plate being symmetric with respect to the ZX plane is as follows: Taking the number of the first electrode plates 301 and the second electrode plates 302 being 2 as an example, the two first electrode plates 301 are respectively on both sides of the first rotation axis Y axis, and the Y axis does not coincide with the central axis of the first electrode plate, that is, the two first electrode plates are symmetric with respect to the Y axis, but a single first electrode plate is not symmetric with respect to the Y axis. The central axes of the two first electrode plates 301 coincide with the second rotation axis Z axis, that is, each first electrode plate is symmetrically arranged with respect to the Z axis. Similarly, the second electrode plates 302 are respectively on both sides of the first rotation axis Y axis, and the Y axis does not coincide with the central axis of the second electrode plate 302, that is, the two second electrode plates 302 are symmetric with respect to the Y axis, but a single second electrode plate 302 is not symmetric with respect to the Y axis. The central axes of the two second electrode plates 302 coincide with the second rotation axis Z axis, that is, each second electrode plate 302 is symmetrically arranged with respect to the Z axis.

[0070] After determining the capacitance signals C1 and C2 generated by the two pairs of first and second plates corresponding to the first rotation axis (Y-axis), the final capacitance signal can be calculated using the formula C1 - C2. Since the rotation angle around the first rotation axis causes the capacitance signals C1 and C2 to change in a negatively correlated manner, that is, when C1 decreases, C2 increases, or when C1 increases, C2 decreases. Calculating the final capacitance signal using the formula C1 - C2 can superimpose the two capacitance signals C1 and C2, thereby improving the capacitance sensitivity. On the other hand, calculating the final capacitance using the formula C1 - C2 can also, to a certain extent, eliminate the change in the capacitance signal caused by the rotation angle around the second rotation axis (X-axis). The rotation around the second rotation axis has a positively correlated effect on the changes in the capacitance signals C1 and C2, that is, when C1 decreases, C2 also decreases, or when C1 increases, C2 also increases. Therefore, calculating the final capacitance using the formula C1 - C2 can, to a certain extent, eliminate the influence of the rotation around the second rotation axis on the capacitance signals C1 and C2.

[0071] In addition, in addition to superimposing multiple capacitance signals using the above formula, other formulas can also be used for comprehensive analysis. For example, using (C1 - C2) / (C1 + C2) to perform differential processing on the results of multiple capacitance signals. In actual applications, other processing can also be performed on the obtained capacitance signals according to the capacitance detection situation, such as correcting or denoising the capacitance signals, etc., to eliminate the noise that affects the calculation result accuracy caused by environmental factors or human operation factors, etc.

[0072] In addition, when the prism carrier 200 rotates only around the second rotation axis, the facing area between the first plate 301 and the second plate 302 should be kept as constant as possible. By doing so, when the prism carrier 200 rotates around the second rotation axis, the facing area between the two plates hardly changes, and only the average distance changes. Therefore, the influence of the rotation around the second rotation axis on the change in the capacitance signal between the first plate 301 and the second plate 302 can be reduced, and the change in the capacitance signal between the first plate 301 and the second plate 302 is more likely to correspond to the angle change of the rotation around the first rotation axis. As Figure 8 shown, the areas of the opposite faces between the first plate 301 and the second plate 302 can be set to different sizes. The area of the first plate in the opposite face is set to be larger than the area of the second plate in the opposite face, and the width of the first plate is greater than the width of the second plate. The direction of the width is the same as the direction of the first rotation axis. Ensure that as Figure 9 shown, when the prism carrier rotates around the second rotation axis (X-axis) within the rated rotation stroke range of ±γ, the plate boundaries of the second plate 302 in the width direction do not move beyond the plate boundaries of the first plate 301 in the width direction, and the facing area between the first plate and the second plate hardly changes.

[0073] In addition, the prism motor further includes: a third electrode plate 303 located on the surface of the prism base 100; a fourth electrode plate 304 located on the surface of the prism carrier 200 and disposed opposite to the third electrode plate; the third electrode plate and the fourth electrode plate form a capacitor. When the prism carrier 200 rotates unidirectionally about the second rotation axis, the facing area between the third electrode plate and the fourth electrode plate increases and the distance between the third electrode plate and the fourth electrode plate decreases, or the facing area between the third electrode plate and the fourth electrode plate decreases and the distance between the third electrode plate and the fourth electrode plate increases; wherein the first rotation axis and the second rotation axis are perpendicular to each other; a processing unit for jointly determining the rotation angle of the prism carrier 200 in space according to the capacitance signal generated by the capacitor formed by the first electrode plate 301 and the second electrode plate 302 and the signal generated by the capacitor formed by the third electrode plate 303 and the fourth electrode plate 304. This can design different electrode plate structures for corresponding detection when the prism carrier 200 can rotate in multiple directions.

[0074] As Figures 10 to 12 shown, when the rotation axis is the X-axis, the third electrode plate 303 and the fourth electrode plate 304 can be arranged at different positions of the prism motor. As Figure 10 shown, the third electrode plate 303 can be arranged at the left side of the base in the figure of the base side portion 102 of the prism base 100, and the position of the fourth electrode plate 304 is correspondingly arranged on the left side surface in the figure of the prism carrier 200. As Figure 11 shown, the third electrode plate 303 can be arranged at the right side of the base in the figure of the base side portion 102 of the prism base 100, and the position of the fourth electrode plate 304 is correspondingly arranged on the right side surface in the figure of the prism carrier 200. As Figure 12 shown, the third electrode plate 303 can be arranged at the rear side of the base in the figure of the base side portion 102 of the prism base 100, and the position of the fourth electrode plate 304 is correspondingly arranged on the rear side surface in the figure of the prism carrier 200.

[0075] In addition, part of the setting rules of the third electrode plate 303 and the fourth electrode plate 304 are the same as those of the first electrode plate 301 and the second electrode plate 302. For example, the number of the third electrode plates is an even number and the third electrode plates are symmetrically arranged based on the rotation axis of the prism carrier 200; the number of the fourth electrode plates is an even number and the fourth electrode plates are symmetrically arranged based on the rotation axis of the prism carrier 200; the third electrode plates and the fourth electrode plates are in one-to-one correspondence, and each pair of the third electrode plate and the fourth electrode plate forms a capacitor. The setting of the third electrode plate and the fourth electrode plate is for detecting the rotation angle of the prism carrier 200 about the second rotation axis. The calculation method refers to the simulation results of the capacitance signal generated by the first electrode plate 301 and the second electrode plate 302 and the rotation angle, which will not be elaborated here.

[0076] In addition, as Figure 13As shown, a part of the positive projection of the first electrode plate 301 in the direction towards the second electrode plate 302 falls outside the second electrode plate 302, and a part of the positive projection of the second electrode plate 302 in the direction towards the first electrode plate 301 falls outside the first electrode plate 301. There is a certain offset shift in the positive projection between the two electrode plates. Similarly, a part of the positive projection of the third electrode plate in the direction towards the fourth electrode plate falls outside the fourth electrode plate, and a part of the positive projection of the fourth electrode plate in the direction towards the third electrode plate falls outside the third electrode plate. There can also be a certain offset shift in the positive projection between the two electrode plates. In order to ensure that within the rated rotation range of the prism carrier 200, the two capacitors formed by the two first electrode plates 301 and the two second electrode plates 302 respectively can both ensure that the change in the facing area is negatively correlated with the average distance, the above effect can be achieved by limiting the value range of shift. The rules for limiting the value range of shift are as follows:

[0077] Taking Figure 6 the first electrode plate 301 and the second electrode plate 302 rotating around the first rotation axis (Y-axis) as an example, according to the above calculation method of the initial plane equation, Figure 6 the minimum initial Z coordinate of the second electrode plate 302 on the left side as shown is , and the maximum initial Z coordinate is . And the plane rotation formula is: ; Using the plane rotation formula, the minimum Z coordinate after rotation and the maximum Z coordinate after rotation are obtained respectively. Through the formula shift > | - |, and shift > | - |, the value range of shift is determined.

[0078] In addition, considering the compactness of the internal structure of the prism motor, the shapes of the first electrode plate 301 and the second electrode plate 302, and the shapes of the third electrode plate 303 and the fourth electrode plate 304 can be other shapes than rectangles. According to the occupancy of the internal space of the prism motor, the electrode plates can be set as triangular electrode plates as shown in Figure 14 , circular electrode plates as shown in Figure 15 or trapezoidal electrode plates and other polygonal or curved electrode plates as shown in Figure 16 , and are combined in pairs.

[0079] An embodiment of the present invention also relates to a method for detecting the rotation angle of a prism motor, which is applied to the above prism motor. As shown in Figure 17 , the method for detecting the rotation angle includes:

[0080] Step 1701: Determine the initial capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate at the initial position of the prism carrier;

[0081] Step 1702: Determine the current capacitance signal when the capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate changes.

[0082] Step 1703: Determine the rotation angle of the prism carrier according to the difference between the current capacitance signal and the initial capacitance signal.

[0083] Compared with the prior art, in the embodiment of the present invention, an electrode plate with a smaller occupied volume is used instead of a Hall sensor in the motor, and the rotation angle of the motor is calculated by the change of the capacitance signal formed between the electrode plates, saving the internal volume of the prism motor occupied, which is beneficial to the miniaturization of the motor. After determining the rotation angle of the prism carrier, the above angle rotation detection method can be used to achieve the anti-shake effect and control the prism carrier to rotate to the target angle. For example, the target angle is the angle required for jitter compensation, and the prism carrier is controlled to rotate according to the difference between the current rotation angle and the target angle. Since jitter occurs in real time during the shooting process, the jitter compensation control is also carried out in real time. After one compensation, it enters the judgment of the next round of compensation angle and the process of controlling the rotation of the prism carrier.

[0084] The calculation method of the corresponding relationship between the capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate and the rotation angle is specifically described in the previous embodiment. Specifically, according to the simulation curve generated based on the capacitance signal and the rotation angle, the rotation angle corresponding to different capacitance signals is determined.

[0085] The step division of the above various methods is only for clear description. When implemented, they can be combined into one step or some steps can be split into multiple steps. As long as the same logical relationship is included, it is within the protection scope of the present invention; adding insignificant modifications to the algorithm or process or introducing insignificant designs, but not changing the core design of its algorithm and process are within the protection scope of the present invention.

[0086] Another feasible embodiment of the present invention relates to a shooting module. As shown in FIG. 18, it includes the prism motor, a lens and an image sensor as described above; the incident light entering the shooting module is reflected by the prism motor and then passes through the lens 400 to reach the image sensor 500. Specifically, the incident light passes through the light-transmitting sheet 201 and enters the interior of the shooting module. The propagation direction of the incident light is changed by the reflecting mirror 202 of the prism motor, so that the incident light can vertically penetrate the lens and reach the image sensor.

[0087] Compared with the related art, the shooting module provided by the embodiment of the present invention is provided with the prism motor provided by the foregoing embodiment. Therefore, it also has the technical effects provided by the foregoing embodiment and will not be elaborated herein.

[0088] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present invention, and in actual applications, various changes can be made to them in form and details without departing from the spirit and scope of the present invention.

Claims

1. A prism motor, characterized in that: include: A prism base, comprising: a base bottom and a base side; A prism carrier, wherein the prism carrier is spaced apart from the prism base, and the prism carrier can rotate relative to the prism base around a first rotation axis and a second rotation axis; the second rotation axis is in the direction of incident light entering the prism motor, the Z axis is in the direction of incident light entering the lens vertically after being reflected, and the first rotation axis is perpendicular to the second rotation axis and the Z axis; A first electrode plate, the first electrode plate is located on a surface of the base bottom of the prism base or a surface of the base side of the prism base perpendicular to the Z-axis direction; a second electrode plate, the second electrode plate is located on the surface of the prism carrier, and the second electrode plate is arranged opposite to the first electrode plate; the first electrode plate and the second electrode plate form a capacitor, and when the prism carrier rotates in one direction around the first rotation axis, the facing area between the first electrode plate and the second electrode plate increases and the distance between the first electrode plate and the second electrode plate decreases, or the facing area between the first electrode plate and the second electrode plate decreases and the distance between the first electrode plate and the second electrode plate increases; The number of the first electrode plates and the second electrode plates are both two, wherein one first electrode plate and one second electrode plate form a group of capacitors, and another first electrode plate and another second electrode plate form another group of capacitors; when the facing area between the first electrode plate and the second electrode plate in one group of capacitors increases and the distance between the first electrode plate and the second electrode plate decreases, the facing area between the first electrode plate and the second electrode plate in another group of capacitors decreases and the distance between the first electrode plate and the second electrode plate increases; when the first electrode plate is located on the surface of the bottom of the base of the prism base, the first electrode plate and the second electrode plate in any group of capacitors have an offset along the Z-axis direction; when the first electrode plate is located on the surface of the side of the base of the prism base, the first electrode plate and the second electrode plate in any group of capacitors have an offset along the second rotation axis direction; The planes where the two first pole plates and the two second pole plates are located are arranged parallel to the first rotation axis, and the two first pole plates are respectively located on both sides of the first rotation axis and are symmetrically arranged compared to the first rotation axis, and the two second pole plates are respectively located on both sides of the first rotation axis and are symmetrically arranged compared to the first rotation axis; the first pole plates are symmetrically arranged based on the second rotation axis of the prism carrier, and the second pole plates are symmetrically arranged based on the second rotation axis of the prism carrier; A processing unit, wherein the processing unit is used to determine the rotation angle of the prism carrier according to a capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate.

2. The prism motor according to claim 1, characterized in that: The length of the first electrode plate is greater than the length of the second electrode plate; wherein the direction defining the length is consistent with the direction of the first rotation axis.

3. The prism motor according to claim 1, characterized in that: Also includes: A third electrode plate, the third electrode plate is located on the surface of the prism base; a fourth electrode plate, the fourth electrode plate is located on the surface of the prism carrier, and the fourth electrode plate is arranged opposite to the third electrode plate; the third electrode plate and the fourth electrode plate form a capacitor, and when the prism carrier rotates in one direction around the second rotation axis, the facing area between the third electrode plate and the fourth electrode plate increases and the distance between the third electrode plate and the fourth electrode plate decreases, or the facing area between the third electrode plate and the fourth electrode plate decreases and the distance between the third electrode plate and the fourth electrode plate increases; wherein the first rotation axis and the second rotation axis are perpendicular to each other; A processing unit, the processing unit is used to jointly determine the angle of rotation of the prism carrier in space based on the capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate, and the signal generated by the capacitance formed by the third electrode plate and the fourth electrode plate.

4. The prism motor according to claim 3, characterized in that: The number of the third pole plates is an even number, and the third pole plates are symmetrically arranged based on the second rotation axis of the prism carrier; The number of the fourth pole plates is an even number, and the fourth pole plates are symmetrically arranged based on the second rotation axis of the prism carrier; The third electrode plates correspond to the fourth electrode plates one by one, and each pair of the third electrode plates and the fourth electrode plates forms a capacitor.

5. The prism motor according to claim 1, characterized in that: The orthographic projection of a portion of the first electrode plate in a direction toward the second electrode plate falls outside the second electrode plate, and the orthographic projection of a portion of the second electrode plate in a direction toward the first electrode plate falls outside the first electrode plate.

6. A method for detecting the rotation angle of a prism motor, applied to the prism motor as claimed in any one of claims 1 to 5, characterized in that: include: Determine an initial capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate when the prism carrier is in an initial position; When a capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate changes, determining a current capacitance signal; The rotation angle of the prism carrier is determined according to the difference between the current capacitance signal and the initial capacitance signal.

7. A shooting module, characterized in that: include: The prism motor, lens and photosensitive chip as claimed in any one of claims 1 to 5; The incident light entering the shooting module is reflected by the prism motor and then passes through the lens to reach the photosensitive chip.

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